Bones undergo a process of constant remodeling consisting of the breakdown of old bone and re-building of new bone. This resorption (by osteoclasts) and formation (by osteoblasts) occurs at an approximately equal rate thereby maintaining strength of the entire skeleton. Bone remodeling enables the renewal of bone mass and is subjected to the influence of a number of hormones and growth factors. It has been shown that melatonin stimulates bone formation through its action on osteoblasts.
Osteoporosis is defined by the World Health Organization (WHO) in women as a bone mineral density 2.5 standard deviations below peak bone mass (20-year-old sex-matched healthy person average) as measured by dual energy X-ray absorptiometry (DXA); the term “established osteoporosis” includes the presence of a fragility fracture.
There are two types of osteoporosis: (1) Primary osteoporosis—bone loss that occurs as a consequence of the normal aging process and most often affects postmenopausal women and (2) Secondary osteoporosis—bone loss that occurs as a consequence of other factors such as a chronic medical condition, nutritional deficiency, or certain types of medications.
Currently, in the United States, several medications are approved by the U.S. Food and Drug Administration (FDA) for the prevention and treatment of osteoporosis and are considered as first-line medications. These medications include bisphosphonates, raloxifene, nasal calcitonin and teriparatide.
While treatment modalities are becoming available (such as the bisphosphonates), prevention is still considered the most efficient way to reduce fracture.
Accordingly, there is a need for novel methods for preventing and/or treating bone diseases such as osteoporosis.
The present description refers to a number of documents, the content of which is herein incorporated by reference in their entirety.